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1Fix the driver behind crashes, sound loss and screen glitches2Repair Windows errors before they cause bigger problems3Scan for outdated or missing drivers - takes under a minuteOn February 14, 2024, Sinn added four models to its U50 dive watch family. Three are regular Hydro versions with oil-filled quartz movements: the U50 Hydro Tegiment, the U50 Hydro S, and the U50 Hydro SDR. The fourth is the U50 S L, a limited edition reported at 500 pieces. It has a luminous dial and a mechanical Sellita SW300-1 automatic movement, which sets it apart from the three Hydro models.
The launch details below come from Fratello Watches’ February 14, 2024 coverage by Jorg Weppelink and from Sinn’s own catalogue. Prices are the figures published at the 2024 announcement. They are not current prices, and availability in 2026 should be checked with an authorized Sinn dealer.
What Sinn added to the U50 range
The three Hydro models share one construction: a 41 mm case, 11.8 mm thickness, oil filling, a Ronda 715Li quartz movement, and a reported 5,000 m water resistance. They differ mainly in external finish. The U50 S L is a different kind of watch: a mechanical limited edition in the conventional U50 format, with a slimmer reported case of 11.2 mm.
| Model | Case and bezel finish | Movement | Case / thickness (as reported) | Water resistance (as reported) | Launch prices (February 2024) |
|---|---|---|---|---|---|
| U50 Hydro Tegiment | Tegiment-treated steel case and bezel | Oil-filled quartz, Ronda 715Li | 41 mm / 11.8 mm | 5,000 m | €2,150 leather; €2,360 silicone; €2,375 stainless-steel bracelet |
| U50 Hydro S | Black hard coating over the Tegiment-treated case and bezel | Oil-filled quartz, Ronda 715Li | 41 mm / 11.8 mm | 5,000 m | €2,550 leather; €2,870 silicone; €3,010 black bracelet |
| U50 Hydro SDR | Steel case with black-coated, scratch-resistant bezel | Oil-filled quartz, Ronda 715Li | 41 mm / 11.8 mm | 5,000 m | €2,240 leather; €2,450 silicone; €2,465 stainless-steel bracelet |
| U50 S L (limited to 500 pieces) | Black-coated Tegimented submarine-steel case; luminous dial | Mechanical automatic, Sellita SW300-1, 42-hour power reserve | Conventional U50 format / 11.2 mm | Not stated for this model in the launch coverage | €2,790 leather; €3,110 silicone; €3,250 black bracelet |
The three Hydro models
Each Hydro model is a variation on the same oil-filled quartz watch, so the choice comes down to finish and strap or bracelet.
#1 Best Overall
- PT5000 Automatic Movement: ML20 uses a PT5000 automatic movement beating at 28,800 vph, with hand winding, hacking seconds, and date display for practical daily use. It gives the watch a smoother mechanical feel while keeping the layout simple and functional for buyers looking for a dependable automatic dive watch
- 200m Water Resistance: Rated to 200m / 20 ATM, ML20 is suitable for swimming, snorkeling, water activities, rain, and daily splashes. The screw-down crown and solid case construction help support the water resistant design, while the compact 39mm case keeps it wearable for office, travel, and regular everyday use
- Sapphire Crystal and BGW9 Lume: The sapphire crystal with inner AR coating helps improve dial clarity and daily scratch resistance. Swiss Super-LumiNova BGW9 on the hands and indices creates a bright blue glow in low light, making the watch easier to read at night, indoors, or during early morning and evening wear
- 120-Click Rotating Bezel: The unidirectional 120-click diving bezel gives ML20 a crisp timing function for water use, short intervals, or daily tasks. The clean tool-watch design, fine sandblasted texture, and available brushed or PVD case options help it feel functional and solid without looking oversized
- Comfortable 39mm Case Fit: The 39mm case, 46mm lug-to-lug length, and 11.3mm thickness give ML20 a compact dive watch profile for many wrist sizes. The solid stainless steel bracelet tapers from 20mm to 16mm, and the 5-hole micro-adjust folding clasp helps fine tune the fit during the day for changing wrist comfort
U50 Hydro Tegiment
This is the standard-finish option. Its case and bezel carry Sinn’s Tegiment treatment on steel, which keeps the watch in the steel-and-treatment look of the core U50 line. It is the least expensive Hydro at every strap configuration in the launch list.
U50 Hydro S
The S adds black hard coating over the Tegiment-treated case and bezel, giving it a stealthier look. It carries the highest launch prices of the three Hydro versions on every strap or bracelet option.
Rank #2
- 12 Hours and seconds Indicator
- Date and Day Indicator
- High Beat 28,800 Bph (4 Hz)
- 100M Meters Water Resistant
- 12 Months Warranty
U50 Hydro SDR
The SDR uses a mixed finish: a steel case with a black-coated bezel that the launch coverage describes as treated for scratch resistance. Its prices fall between the Tegiment and the S on each configuration.
The U50 S L limited edition
The U50 S L is the only model in this group that is not oil-filled quartz. It uses the conventional U50 format and a Sellita SW300-1 automatic movement with a reported 42-hour power reserve. Its case is a black-coated Tegimented submarine steel, and the defining feature is the luminous dial.
Recommended Free Tools
Rank #3
- 12 Hours and seconds Indicator
- Date and Day Indicator
- High Beat 28,800 Bph (4 Hz)
- 100M Meters Water Resistant
- 12 Months Warranty
The launch coverage reports the edition at 500 pieces. Because the number was stated at launch, buyers should confirm with a dealer whether any pieces remain before assuming availability.
Oil-filled quartz or mechanical: how the two designs differ
The Hydro trio and the U50 S L answer different buyer needs. The table below separates the points that the sources actually establish from those they do not.
Rank #4
- 9H Hardness can effectively resist daily scratches.
- Dust-free,bubble free,one-push super easily installation.
- Oleophobic Screen Coating protects against sweat and oil residue from fingerprints.
- 0.33mm thick keep the screen responsive to every touch and tap.
- Extreme clarity preserves the original screen brightness and definition, ensuring viewing experience.
| Point | Hydro models (Tegiment, S, SDR) | U50 S L | Conventional U50 (Sinn catalogue 2025/2026) |
|---|---|---|---|
| Movement type | Quartz, oil-filled | Mechanical automatic, Sellita SW300-1 | Not stated in the catalogue entry used for this comparison |
| Reported battery life | 60 months, with an end-of-life indicator | Not applicable (automatic) | Not applicable to the catalogue entry used here |
| Reported power reserve | Not applicable (quartz) | 42 hours | Not stated |
| Reported functional temperature range | −20°C to +60°C | Not stated in the launch coverage | Not stated |
| Case diameter | 41 mm | Conventional U50 format (41 mm per the catalogue) | 41 mm |
| Case thickness | 11.8 mm | 11.2 mm | Not stated |
| Water resistance | 5,000 m as reported at launch | Not stated in the launch coverage | 500 m / 50 bar |
| Case material | Tegiment-treated steel or steel with coated bezel | Black-coated Tegimented submarine steel | German Submarine Steel |
The Hydro water-resistance figure of 5,000 m and the catalogue’s 500 m / 50 bar rating describe different configurations. Do not read one as an update to the other.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Specifications the sources do not confirm
The launch coverage gives no verified lug-to-lug measurement for the Hydro watches. Any figure near 47 mm should be treated as an estimate, not a published specification. The same applies to any performance claim: the figures above are product specifications as reported at launch, not results from independent testing.
Which model fits which buyer
- You want the stealthiest Hydro: the S has the black hard coating over the Tegiment-treated case and bezel.
- You want a Hydro with a steel case and dark bezel: the SDR offers a steel case with a black-coated, scratch-resistant bezel.
- You want the most conventional finish at the lowest launch price: the Tegiment is the standard-finish Hydro.
- You want a mechanical movement and a luminous dial: the U50 S L is the only model in this group with both, and it is limited to 500 pieces.
Checking availability before you buy
Because the prices and edition figures date from February 2024, confirm the following before committing:
- Confirm the exact model name and whether the strap or bracelet you want was offered in that configuration.
- Ask an authorized Sinn dealer for the current price in your market, since launch prices may have changed.
- For the U50 S L, ask whether any of the 500 pieces remain.
- Check the Sinn catalogue for the current U50 range before comparing against the 500 m / 50 bar conventional rating.
Sources: Fratello Watches, Jorg Weppelink, “Sinn Extends Its U50 Lineup — Three Regular Oil-Filled Models And A Lume-Dial Limited Edition,” February 14, 2024. Sinn Spezialuhren, Sinn Catalogue 2025/2026.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
